fix url
Merge pull request #80 from xuwei-k/fix-url

fix url
Added release notes for 6.0.3.
Update 6.0.3.markdown
6.0.3 is available.
Cherry-picked scala-2.11 / sbt 2.13 changes from 732f1b7a6cf1005be514d6339ebee61f7587c90e
Update specs version for tests on master.
Disable tests on 2.11 until specs is built for it.
Updated to latest scalaz / specs2. Fixes #86.